This is the conversion ratio between two solid-angle measures: steradians and degree-square's, applicable to integration infinitesimals. The deg^2 must not be confused with a finite spherical square having one degree side (see A231983, A231984, A231985), just as one steradian must not be confused with the solid angle covered by a spherical square with a side arc-length of one radian (see A231986, A231987).

Equals also full solid angle expressed in degrees, divided by 4Pi (i.e., A125560/4Pi).